Fluid couplings and fittings are widely employed to interconnect components of conduit systems. For instance, self-sealing valved couplings are often utilized at the ends of hose lines wherein uncoupling of the mating parts automatically causes valve components within the parts to close to prevent fluid leakage. Assembly of the coupling parts automatically opens the valves to reestablish fluid flow between the coupling parts.
Self-sealing couplings and fittings commonly employ axially moveable valves of the sliding sleeve or poppet type which utilize the relative axial movement of the coupling parts during assembly or disassembly to open or close the valves, respectively. Poppet and sleeve type valves usually include ports and flow paths having an axis which is perpendicularly or transversely disposed to the axis of the associated fitting passage, and due to the torturous flow path through or around the valve considerable resistance to fluid flow is produced. Further, high turbulence is created due to the fluid rapidly changing direction during flow through the fitting, and pressure losses may be significant. Sleeve and poppet valves often utilize springs to bias the valves toward the closed condition, and while valves of this type are capable of automatic operation controlled by the assembly and disassembly of the coupling parts the adverse fluid flow characteristics have been tolerated as alternate constructions were not available which were practical and dependable in operation, particularly with respect to the automatic self-sealing feature.
Ball valves employing a spherical ball element having a large diametrical flow passage bore are used in conduit systems wherein high capacity, low flow resistance characteristics are required. As the bore within a ball valve is often of a diameter equal to the passage within the associated fitting, the valve, itself, offers little restriction to fluid flow, and as only a 90.degree. rotation of the ball valve is required between full open and closed positions such valves are quick acting. However, ball valves usually require an external operator, such as a lever or handle, for rotating the ball valve between open and closed positions, and ball valves have not been readily adapted to self-sealing coupling use wherein the ball valve element must pivot between open and closed conditions depending on whether the coupling parts are connected or disconnected. Preferably, self-sealing valved fittings are fully automatic wherein the valve operation is solely determined by the coupling and uncoupling action of the parts, and no manual valve operation is necessary.
It is an object of the invention to provide a self-sealing fitting utilizing a ball valve which is automatically displaced between open and closed conditions solely by the act of coupling and uncoupling the fitting to other parts of the flow system.
Another object of the invention is to provide a self-sealing fitting for controlling fluid flow utilizing an automatically operated ball valve wherein the ball valve is operated between open and closed conditions solely by axial forces imposed thereon during coupling and uncoupling of the fitting.
A further object of the invention is to provide a self-sealing fitting utilizing a ball valve which produces little restriction to fluid flow through the valve, and wherein the ball valve is rotated between open and closed conditions by the act of coupling the fitting to another fitting, or the uncoupling thereof, respectively, axial forces imposed upon the ball valve determining the rotation of the valve between its open and closed conditions.
Yet another object of the invention is to provide a self-sealing fitting utilizing a ball valve having a pivot offset with respect to the ball center and bore, such that axial displacment of the ball valve within the fitting passage while axially restraining the pivot causes the ball valve to rotate between open and closed conditions solely due to its axial displacement.
In the practice of the invention the fitting body includes a passage through which fluid flow occurs. A ball valve is located within the passage having an exterior spherical surface and a diametrical bore of a diameter substantially equal to the fitting passage. The ball valve includes pivot pins extending from the spherical surface defining an operating pivot axis which is off-set relative to the center of the ball valve and relative to the valve bore. An annular groove defined within the passage receives the pivot pins restraining the same against passage axial displacement, but permitting rotation and radial displacement of the pivot.
An annular valve seat is slidably displaceable within the fitting passage and is sealed with respect to the passage by a seal ring engaging a cylindrical surface. The valve seat also includes an annular seal sealingly engaging the spherical exterior surface of the ball valve, and the valve seat bore is of a diameter substantially equal to the ball valve bore. An annular collar is located in the fitting passage upon the opposite side of the ball valve with respect to the valve seat and is also axially displaceable, and a compression spring biases the collar into engagement with the ball valve and biases the ball valve into engagement with the valve seat. Axial displacement of the collar, ball valve and valve seat is limited by a stop defined within the fitting passage. An internal thread is concentrically formed within the passage adjacent the valve seat stop for receiving a conduit adapter which couples with the fitting.
The support of the ball valve by the valve seat and collar permits the ball valve to rotate within the fitting passage solely by axial forces being imposed upon the ball valve through its associated valve seat or collar. Such axial forces rotate the ball valve due to the offset position of the valve pivot wherein a torque is imposed upon the ball valve during axial displacement thereof and the valve will rotate while its center remains coincident with the fitting passage axis.
The biasing force imposed upon the ball valve by the spring biases the ball valve toward the fitting "open" end until the valve seat engages its stop. Under this condition the valve bore will be perpendicularly disposed to the axis of the fitting passage, and in this condition the valve seat will not communicate with the valve bore and the fitting passage is closed with respect to fluid flow therethrough. This is the normal uncoupled condition of the fitting.
Upon the coupling of another fitting, adapter or other coupling half to the fitting by means of an annular stem engaging the passage threads the valve seat is engaged and axially displaced away from its stop compressing the collar spring. This axial movement of the valve seat, ball valve and collar causes the ball valve to rotate due to the rotational force imposed on the ball valve by the pivot, and upon full connection of the fitting with its associated coupling part the ball valve will have rotated 90.degree. to align the valve bore with the fitting passage to "open" the passage to full unrestricted flow. Removal of the associated fitting by unthreading the stem permits the spring to move the collar, ball valve and valve seat toward the stop pivoting the ball valve toward its closed condition such that complete uncoupling results in the ball valve being fully closed and the fitting is "self-sealed".
From the above description, it will be appreciated that rotation of the ball valve between open and closed conditions is solely produced by axial forces imposed upon the ball valve by its valve seat or biasing collar.